Análogos das prostaglandinas diminuem a sensibilidade do teste provocativo da ibopamina no glaucoma

PURPOSE: To evaluate the ibopamine provocative test for the diagnosis of glaucoma in glaucoma patients using antiglaucomatous drugs. METHODS: Two 2% ibopamine eyedrops were instilled 5 minutes apart in one eye selected at random in both glaucoma and normal subjects. The intraocular pressure (IOP) was assessed prior to the drops and 30, 60 and 180 minutes after instillation. The test was considered positive when there was an intraocular pressure increase of greater than 4 mmHg at any one of the time-points. The amount of intraocular pressure change was compared to the types of medical treatment. RESULTS: Fifty-eight eyes were included (38 glaucoma patients and 20 normal individuals). The intraocular pressure rise was significantly higher in glaucoma patients (p<0.001 at all times). The sensitivity and specificity of the ibopamine test were 68% (87% if we exclude eyes using prostaglandin analogues) and 95%, respectively. Glaucoma patients using prostaglandin analogues did not present a significant intraocular pressure elevation. CONCLUSION: The ibopamine provocative test may be an auxiliary test in glaucoma diagnosis. Despite the small sample size, concurrent use of prostaglandin analogues apparently reduces the test's sensitivity.